
grades_judgment = int(input('输出您的成绩：'))
if 90 <= grades_judgment <= 100:
     print('A')
elif 80 <= grades_judgment < 90:
    print('B')
elif 60 <= grades_judgment < 80:
     print('C')
elif 0 <= grades_judgment < 60:
    print('D')
else:
     print("请输入0-100数字")

